noun
general resemblance; largely the same
Often used in the set phrase 大同小異 (largely the same with minor differences). As a standalone noun, it is somewhat literary and less common in everyday speech.
See also: 大同小異
両者の意見は大同小異だ。
Their opinions are much the same with only minor differences.
大同
Since they are largely the same, please don't worry about the small details.
noun
uniting with a common goal
Primarily appears in the compound 大同団結 (a grand coalition or union for a common purpose). Rarely used independently in modern Japanese.
See also: 大同団結
大同団結を呼びかける。
Call for a grand coalition.
「大同」は、共通の目的のために団結することを表す語として使われることがある。
大同 is sometimes used to express uniting for a common purpose.
noun
Daidō era (806-810)
Historical Japanese era name. Used only in historical contexts.
大同元年は西暦806年にあたる。
The first year of the Daidō era corresponds to 806 CE.